Hi! Nice that you also have submitted a game, I liked the feeling of movement, but I had a lot of issues with other parts of the game.
I can agree with the z-fighting textures. Textures are clipping on the buildings. The zombies seem to be equally slow and do not pose any thread, sounds and effects/polish is a bit lackluster. There is no cap on the x rotation of the player, so I could look upwards until I was upside down, and the controls were inverted, this was a fun additional challenge. Fog was a nice effect. It was atmospheric to a part, but the floating gun and the sounds broke immersion.